Pumping apparatus for encapsulating machine



Feb. 22, 1966 5, HA$MAN 3,236,185

PUMPING APPARATUS FOR ENCAPSULATING MACHINE Original Filed April 15, 1960 7 Sheets-Sheet 1 INVENTOR. 70A/6Y ,4 62/4; M4

BY a E Feb. 22, 1966 5 c s 3,236,185

PUMPING APPARATUS FOR ENCAPSULATING MACHINE Original Filed April 15. 1960 7 Sheets-Sheet. 2

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PUMPING APPARATUS FOR ENCAPSULATING MACHINE Original Filed April 15. 1960 7 Sheets-Sheet 4 FIG. 4

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PUMPING APPARATUS FOR ENGAPSULATING MACHINE Original Filed April 15, 1960 7 Sheets-Sheet 5 I N VENTOR. 53 04/5/ ,4 (A 45444 BY Mdw Feb. 22, 1966 5, CHASMAN 3,236,185

PUMPING APPARATUS FOR ENCAPSULATING MACHINE Original Filed April 15, 1960 7 Sheets-Sheet 6 I NVENTOR. 5/04/5/ ,4 fb ASMAM/ BY a United States Patent 3,236,185 PUMPING APPARATUS FOR EN CAPSULATING MACHINE Sydney A. Chasman, 1350 Outlook Drive, Mountainside, NJ.

Original application Apr. 15, 1960, Ser. No. 22,520, now Patent No. 3,092,942, dated June 11, 1963. Divided and this application Mar. 18, 1963, Ser. No. 265,634

8 Claims. (Cl. 103-38) This application is a divisional of my copending application Serial No. 22,520, entitled Apparatus and Method For Encapsulating Machine filed April 15, 1960, which issued on June 11, 1963 as US. Patent No. 3,092,942.

The present invention generally related to pumping apparatus for a machine for making fluid filled capsules, and more particularly to a device for pumping predetermined quantities of fluid into capsules formed from continuous quantities of fluid into capsules formed from continuous sheets of plastic film.

In the operation of an encapsulating machine, means must be provided to transport the fluid to the capsules, and to control the quantity of fluid flowing to each capsule. The importance of providing a means for accurately predetermining the quantity of fluid to be placed in each capsule, and for delivering an identical quantity of fluid to each capsule is particularly obvious with regard to drug commodities where the necessity for specified dosages within each capsule is an absolute requirement. It is therefore significant to the proper operation of any encapsulating machine to have a pum which can reliably and accurately measure the quantity of fluid to be delivered on each pump stroke and hence to each individual capsule, and to provide means for varying this quantity while the machine is in operation so that accurate deliveries may be maintained.

In the operation of an encapsulating machine, it has heretofore been difficult to control the quantity of fluid supplied to each capsule and to make changes or adjustments of such quantity without stopping the operation of the pump. The present invention relates to a pumping apparatus for an encapsulating machine which is a significant improvement over the prior art in that it makes possible the delivery of predetermined accurate charges in that means are provided for regulating the quantity of fluid delivered without shutting down the operation of the machine, and in that means are further provided for preventing leakage or contamination of fluid while the machine is in operation. It is an object of the present invention to provide a fluid metering pump which accomplishes one or more of the aforestated purposes.

Another object is to provide a fluid pumping -apparatus which will reliably and accurately deliver predetermined charges of fluid as required.

A further object is to provide a pump which will deliver predetermined, accurate charges and which may be adjusted to varying the size of the charge to be delivered without stopping the operation of the pump.

The pumping apparatus, to be described, supplies fluid to a number of nozzles, and therefore, contains a piston within a cylinder as the fluid delivery means for each nozzle. The pistons are continuously reciprocated within the pump body in timed relationship with the indexing of the cylinders so as to draw fluid from a supply reservoir and deliver it under pressure to the filling nozzles at appropriate times during the cycle of operation. The fluid delivery is under the control of valves which are re'leasably driven from the pump driving means, such that a single supply reservoir provides fluid for all the pumping cylinders, and such that the discharge of fluid can be interrupted without stopping the operation of the 3,236,185 Patented Feb. 22, 1966 pump. When these valves are released from the driving means, the pump pistons continue to operate thus agitating the fluid and maintaining a homogeneous mixture within the supply reservoir. Valve lock means are further provided to positively seal the seats between the valves proper and their associated passageways during the intake and discharge movements of the pump pistons, thus preventing leakage of fluid or contamination thereof. During the intervals when the valve mechanism is being reciprocated between intake and discharge positions, means are provided for relaxing the sealing pressures of the valve lock means thus reducing the power required to move the valves and facilitating the efficient operation of the pump. In addition, means are provided for varying the duration of the pump stroke without stopping the operation of the pump, and thus providing reliable means for controlling the quantity of fluid delivered.

The above brief description as well as further objects, features and advantages of the present invention, will be more fully appreciated by reference to the following detailed description of a presently preferred embodiment when taken in conjunction with the following drawin-gs, wherein:

FIG. 1 is a plan view, with parts in section, showing an encapsulating machine in accordance with the present invention, with the pump unit removed to show the manifold block;

FIG. 2 is a fragmentary vertical cross section view showing the filling fluid pump drive, fluid pipes, cylinders and cams;

FIG. 3 is a vertical section of the encapsulating machine taken along the line 3-3 of FIG. 2 and from the front of the machine showing details of the cam drive assem- 'blies;

FIG. 4 is a top plan view of the metering pump, partly in section, and with the fluid supply container removed;

FIG. 5 is a side elevation of the metering pump taken along line 5-5 of FIG. 4;

FIG. 6 is a rear elevation view of'the metering pump taken along the line 6-6 of FIG. 5;

FIG. 7 is a front elevation view of the metering pump taken along line 7-7 of FIG. 5;

FIG. 8 is a vertical cross section view of the metering pump, taken along line 8-8 of FIG. 4;

FIG. 9 is a perspective rear face view of the pump valve cam and clutch release cam with related cam followers and portions of the linkages leading to the members to be operated thereby; and

FIG. 10 is a cam chart illustrating the relative timing of various operations of the pump throughout a cycle of operation.

The pump mechanism which supplies, under pressure the fluid for filling the capsules and its driving arrangements will now be more particularly described with reference to the a foredescribed drawings. Pump 24 includes a central body casting 270 (FIGS. 4 to 8 inclusive) having generally T-shaped front and rear end plates 272 and 274 respectively bolted or otherwise removably secured to each end. The leg of each T carries vertically extending guide slots 276 and 277 within which is slidaibly mounted the ends of piston slipper block 278. Pivotally mounted to the slipper block 278 at the front and rear ends thereof, are connecting rods 280 and 282, respectively. These are connected to crank arms 281, 283 respectively, carried by crank shaft 285. Thus as crank shaft 285 is oscillated, the slipper block 278 is reciprocated vertically carrying with it a number of piston rods 286 each of which is received in an individual cylinder 288 in pump body block 270. Each piston is sealed in its respective cylinder 288 by conventional pump packing gland 290. Each cylinder 288 is connected to a valve 296 by a transfer port 292. Further passageways are drilled in the pump body block 270, inlet passage 293 connecting valve 296 to the fluid distributor chamber 295 and discharge passage 294 connectring valve chamber 296 to the individual pipes 28. Valves 296 are generally cylindrical bodies having passageways 297 which, as valve 296 is oscillated, alternately connects the fluid supply 295 to cylinder 288 or connects the discharge channel 294 to the cylinder 288. Thus, as piston 286 is drawn downwardly, valve 296 is in its most counterclockwise position as shown on the left side of FIG. 8, and the atmospheric pressure on the fluid supply causes fluid to be drawn into the cylinder. As valve 296 is rotated to its most clockwise position and the piston 286 reverses its stroke the fluid will be delivered under pressure through "pipes 28, for filling the capsules. Since the pressure required to fill the capsules is rather high, leakage between the seats of the valve chambers 296 and the transfer ports could conceivably take place. This is prevented by providing valve seal lock members 298 mounted in a series of guide blocks 29-1 and each having a wedge surface 300 adapted to be pressed firmly against valve 296 by spring 301. Thus leakage is positively prevented. The top end of lock member 298 is adapted to cooperate with cam 303. Cam 303 is generally cylindrical, but has a flat sector 302 on its periphery. When flat sector 302 is presented to lock member 298 the valve body is pressed against the valve ports by spring 301 coacting with Wedge surface 300 so that the cylindrical surface of the cam 303 engages the end of lock member 298, compresses spring 301 and relieves the pres-sure of the wedge face 300 against the valve 296. Cams 303 are carried on cam shafts 304 journalled on the right and left arms of the T-shaped end plates by front bearings 306 and rear bearings 307 respectively. Cam shafts 304 are each provided at their rear ends with a transversely extending key slot 308 adapted to couple with extending keys on shafts 3 and 312 which are journalled in bearing plates 170 and 171 (see FIG. 1) and are coupled to actuating means within the forming and filling mechanism 18. Valves 296 for the right and left hand sides of the pump are also provided with key slots transversely of rear ends thereof, adapted to be coupled to valve drive shafts 314 and 316 respectively. Coupling keys 311, 313, 315, 317 inclusive, carried by drive shafts 310, 312, 314 and 316 respectively, are so keyed to the shafts that they will not turn on shafts but are free for longitudinal movement along the shaft ends and are spring pressed towards the front of the machine so that they engage with the key slots in their respective driven shafts for positive rotation thereof. A similar quickly removable coupling 318 (see also FIGS. 2 and 3) is provided with and between pump crank shaft 285 and its drive shaft 319 so that the Whole pump mechanism may be readily removed as a unit. Coupling 318 has a pair of extending pins 309 adapted to enter holes 309 on crank 283 todrive crank shaft 285. When mounted, pump 24 is secured to front mounting plate 170 in appropriate aligned relationship with its operating shafts by mounting rails 320 and 322 being received in mounting holes, 321 and 323, respectively in back end plate 274 and mounting holes 324 and 325 in front end plate 272. The pump is held in place by combined threaded studs and locating pins 326 and 327 mounted on front mounting plate 170 and engaging with mounting holes 328, 329 in end plate 274.

Pump 24 is continuously operated during the entire time that the encapsulating machine is in operation by the mechanism now to be described. Intermediate shaft 153 is coaxial with shaft 234. Shaft 153 bears a pump cam assembly 330 (-FIG. 3). Pump cam assembly 330 is embraced by the arms of an eccentric follower fork 332 clamped to pump shaft 334. Pump earn 330 could conveniently be a single disc eccentrically mounted on 4 shaft 153 and embraced by fork 332. This would result in substantially uniform motion of the pump pistons driven thereby. However, to avoid pumping action while transferring valve 296 between inlet and outlet positions, it is preferred to flatten the pressure curve 8 (FIG. 9) in the 45 -90 and 225 270 segments and shorten the intervening suction and discharge strokes. In order to attain this result cam 330 is actually formed as two offset cams 331, 331 and follower fork 332 has its arms offset so that one follows cam 331 and the other 331 Appropriate contouring of the cam faces provides for the shortened suction and delivery strokes and the longer dwells at the ends thereof. The shaft 334 also carries, rigidly secured to it, arm 336 extending approximately at right angles to the length of the follower fork 332. The far end of arm 336 is pivotally secured to one end of lever 338 by pin 337. Lever 338 swings about movable pivot 339 slidable along the length of lever 338. The end of lever 338 is swingably coupled to link 340 by means of a pin 341 and link 340 is coupled to crank arm 342 carried by operating shaft 319. Thus as the cam 330 rotates, the cam follower fork 332 is oscillated back and forth through an arc determined by the degree of eccentricity of cam 330 and the pump operating shaft 319 is consequently oscillated. The particular angle of oscillation of pump operating shaft 319 is determined by the relative position of movable pivot 339 along the length of lever 338. Pin 339 is supported in journals on a pivot support carriage 344, j-ournalled on axle 345 and carrying at an intermediate point between its ends a pivot adjusting nut 348. Axle 345 for pivot support carriage 344 is supported forwardly of the front mounting plate (see FIG. 2). Nut 348 is threaded onto lead screw 350 mounted in bearing block 351 and coupled by a bevelled gear pair 352 further shaft 353 which carries an adjusting knurled knob 354 (FIG. 1). As knob 354 is rotated, nut 348 can be caused to progress along lead screw 350 in one direction or the other. This action effectively shifts movable pivot 339 along the length of lever 338. It should be noted that the construction permits such shifting without stopping the operation of the pump. Thus the effective length of pump stroke is varied as desired to adjust the amount of fluid charged delivered to the nozzles into the capsules being formed, the valves of pump 24 being operated in appropriate timed relationship so that the fluid charge is delivered to the nozzles. Valves 296 are however not continuously operated as the pump pistons are operated, but are driven by a separate drive means which can be coupled and uncoupled from the remainder of the drive so as to selectively cause the pump to either deliver the charge to the capsules or, in the event the pump valve operating mechanism is disconnected so that the pump valves 296 are in the position shown in FIG. 8, the fluid contained within reservoir 294 will merely be circulated into and out of the cylinder cavity in which pistons 286 operate. This has the function of keeping the fluid continuously stirred up during times when fluid charges are not being delivered to the forming capsules. Pump valves 291 are operated in timed relationship to the operation of the pump pistons by cam 158 when it is clutched to gear 122 adjacent thereto on shaft 124 on which both are mounted. Cam 158 carries on its rear face a shrouded cam track 356 in which rides cam follower finger 358 carried by cam follower arm 360, journalled on shaft 361. Cam [follower arm 360 carries extension arm 362 coupled to link 364 at a point intermediate rits ends. The ends of link 364 are pivotally coupled to cranks 365 and 366 mounted on shafts 315 and 316 respectively. Thus as cam 158 rotates, cam follower arm 360 is oscillated back and forth and this oscillatory motion is carried by link 364 and cranks 365 and 366 to shafts 315 and 316. The latter shafts are directly cou pled to the ends of valves 291 so that the valves are oscillated from a position in which the receding pistons draw fluid from fluid reservoir chamber 295 to a position where rising piston 286 delivers a measured charge of fluid to the capsule being formed. Pivotally mounted on shaft 371 for separate rotation thereon is a second cam follower arm 368, having a cam follower finger 369 riding in valve lock operating groove 370 likewise on the rear face of cam 158. Cam follower 368 has an extension arm 372 extending upwardly from shaft 371 and coupled at its top end to crank 376. Cranks 376 and 378 are mounted on valve lock operating shafts 310 and 312 respectively, and coupled together by link 374. Thus, as cam 158 rotates while in coupled relationship with gear 122, shafts 310 and 312 are rocked as dictated by the profile of cam track 370 and the valve lock cams are alternately rotated from positions in which the valve lock members 298 are free from contact with valves 296 and to positions wherein spring 301 causes the valve locks 298 to bear against valves 2% and lock them so as to prevent leakage between the valve passages and the valve face. The relative timing of these operations is illustrated in the cam time chart, FIG. 9. Curve 8 shows that the pump piston stroke is continuous having its delivery strokes running from 90 to 225 along the length of the chart whereas the suction stroke runs from 270 to 45 therealong. It will be noted from curve 5 of the pump valve transfer diagram, that the position of the pump valve 296 is shifted from intake to delivery positions during the time intervals of 45 to 90 and from 225 to 270.

In order to facilitate a more thorough understanding of this embodiment of the pumping apparatus, there will now be described a typical sequence of operations:

Crankshaft 285 is driven by drivesha'ft 319. The coupling between these shafts is accomplished by a pair of extending pins 399 of coupling 318 adapted to enter a pair of holes 309 of crank 283. As crankshaft 285 is oscillated, crank arms 281, 283 respond to such oscillatory motion causing connecting rods 280, 282 to reciprocate vertically. Slipper block 278 is vertically reciprocated carrying with it piston rods 286, which piston rods are drawn from and returned to cylinder 288 thereby completing a piston stroke. As piston 286 is drawn downward, a force, produced by the diiference between the pressure within the cylinder and atmospheric pressure, is communicated from cylinder 288 to valve 296 drawing fluid into valve 296. This is effectuated without leakage because valve 296 is in its most counterclockwise position secured to the inlet passage 293 by the pressure of valve seal look member 238.

When piston 286 is being driven upward into cylinder 288, the fluid in valve 2% is forced through discharge passage 294 into pipes 28 for filling the capsules, this also being effectuated without leakage, because valve 2% has been oscillated to its most clockwise position wherein it communicates with the discharge passage 294 and wherein it is secured against leakage by the pressure of the valve seal lock member 298.

The rotation of cam 303, which cam rides along the end of lock member 298, causes the wedge face 380 to be pressed against the valve 296 by means of the pressure of spring 301 against lock member 298 during both the intake and discharge positions, and causes the pressure against the spring 301 and hence against the wedge face 300 to be relieved when the flat face 302 of cam 303 ridges along lock member 298, thus providing intervals for oscillatory motion of valve 296.

When the pressure against the wedge face 300 is thus relieved, crankshaft 285 is oscillated thereby oscillating valve 296 between the intake and discharge positions and thereby causing reciprocation of the pistons 286 in the cylinders 288.

Likewise, the pump valves 291 are operated in timed relationship to the operation of the pump pistons 286. This is accomplished by rotation of cam 158 thus oscillating cam follower arm 368 which oscillatory motion is transmitted to the valves 291 such that valves 291 are oscillated from a position in which the receding pistons draw fluid from reservoir chamber 295 to a position where rising piston 286 delivers a measured charge of fluid to the capsule being formed. Cam 158 is also interrelated to the operation of the valve lock cams 303, as aforestated, thus sequencing the rotation of cams 303, and hence delineating the sequence of operation of the wedge looks, as aforestated.

The piston stroke is controlled by the pump cam assembly 330 borne on shaft 153. Pump can assembly 330 is embraced by the arms of an eccentric follower fork 332, which follower fork is in turn coupled to an extending arm 336, which extending arm is pivotally secured to one end of a lever 338 by pin 337. Lever 338 swings about movable pivot 339, which pivot is slidable along the length of lever 338. The eflective length of the pump stroke is varied by varying the position of pivot 339 along the lever 338, and the size of the charge delivered is thus determined by the position of pivot 339 along lever 338.

There is provided pumping apparatus of relatively simple construction and operation which will reliably and accurately transport predetermined quantities of fluid from a reservoir to a series of outlet passages from whence capsules may be filled. Moreover, the reliability of this device may be insured by the provision of means to prevent leakage or contamination of the fluid when subjected to the relatively high pressures of the pumps operation and by the provision of means for continuously adjusting and balancing the charge output to each capsule without closing down the operation of the pump.

While but one embodiment of the present invention is here described, it should be clearly understood that this invention is not limited to the description as herein presented and should be construed broadly to give effect to the novel features defined in the appended claims.

What I claim is:

1. A pump comprising a pump cylinder having a transfer port connected therewith, a piston reciprocable in said cylinder, a supply reservoir, an outlet passage, an oscillating rotary valve for controlling flow through said transfer port and oscillatable between an intake position wherein it establishes communication from said supply reservoir to said transfer port and a discharge position wherein it establishes communication from said transfer port to said outlet passage, driving means for continuously reciprocating said piston, mechanism for oscillating said valve between said two positions in timed relationship to the reciprocation of said piston where-by fluid from said reservoir is delivered to said outlet passage spring-pressed wedge pins adjacent to said rotary valve in opposed relationship with said ports to press said valve tightly against said ports to prevent leakage of fluid about said valve, and means coupled to said mechanism for relaXing pressure of said wedge locks during intervals when said valve is in oscillatory motion.

2. A pump comprising a pump cylinder having a transfer port connected therewith, a piston reciprocable in said cylinder, a supply reservoir, an outlet passage, an oscillating rotary valve for controlling flow through said transfer port and oscillatable between; an intake position wherein it establishes communication from said supply reservoir to said transfer port and a discharge position wherein it establishes communication from said transfer port to said outlet passage, driving means for continuously reciprocating said piston, mechanism for oscillating said valve between said two positions in timed relationship to the reciprocation of said piston whereby fluid from said reservoir is delivered to said outlet passage, means for disconnecting said mechanism when said rotary valve is in the said intake position, a spring-pressed Wedge adjacent to said rotary valve in opposed relationship with said ports whereby said valve is tightly pressed 7 against said ports to prevent leakage of fluid about said valve, and means coupled to said mechanism for relaxing pressure of said wedge during intervals when said valve is in oscillatory motion.

3. A variable delivery pump comprising a pump cylinder having a transfer port connected therewith, a piston reciproca ble in said cylinder, a supply reservoir, an outlet passage, an oscillatory rotary valve for controlling flow through said transfer port and oscillatable between an intake position wherein it establishes communication from said supply reservoir to said transfer port and a discharge position wherein it establishes communication from said transfer port to said outlet passage, driving means for continuously reciprocating said piston, mechanism for oscillating said valve between said two positions in timed relationship to the reciprocation of said piston whereby fluid from said reservoir is delivered to said outlet passage, and means included in said driving means for varying the quantity of fluid delivered by said pump, said means including a rotary eccentric and a follower fork coupled to said eccentric, an oscillatable crank arm connected to said piston for reciprocating said piston, a lever connecting said follower fork and said crank arm, said lever having a stationary pivot intermediate its ends, and means for shifting said pivot along the length of said lever whereby the stroke of said pump may be varied.

4. In a pump comprising a pump cylinder having a transfer port connected therewith, a supply reservoir, an outlet passage, a piston reciprocable in said cylinder, an oscillatory rotary valve for controlling flow through said transfer port and oscillatable between an intake position wherein it establishes communication from said supply reservoir to said transfer port and a discharge position wherein it establishes communication from said transfer port to said outlet passage, driving means for continuously reciprocating said piston, and mechanism for oscillating said valve between two positions in timed relationship to the reciprocation of said piston whereby fluid from said reservoir is delivered to said outlet passage, means for disconnecting said mechanism only when said rotary valve is in the intake position, a spring-pressed wedge adjacent to said rotary valve in opposed relationship with said ports whereby said valve is tightly pressed against said ports to prevent leakage of fluid about said valve, means coupled to said mechanism for relaxing the pressure of said wedge during intervals when said valve is in oscillatory motion, and means included in said driving means for varying the quantity of fluid delivered by said pump.

5. A pump comprising a pump cylinder having a transfer port connected therewith, a piston reciprocable in said cylinder, a supply reservoir, an outlet passage, an oscillating rotary valve for controlling flow through said transfer port and oscillatable between an intake position wherein it establishes communication from said supply reservoir to said transfer port and a discharge position wherein it establishes communication from said transfer port to said outlet passage, driving means for continuously reciprocating said piston, mechanism for oscillating said valve between said two positions in timed relationship to the reciprocation of said piston whereby fluid from said reservoir is delivered to said outlet passage, spring-pressed wedge pins adjacent to said rotary valve in opposed relationship with said ports to press said valve tightly against said ports to prevent leakage of fluid about said valve, means coupled to said mechanism for relaxing pressure of said wedge locks during intervals when said valve is in oscillatory motion, and coupling means for interconnecting said pump with a driving shaft, said means including a crankshaft and coupling pins projecting longitudinally from the outer end surface of said crankshaft.

6. A variable delivery pump comprising a pump cylinder having a transfer port connected therewith, a piston reciprocable in said cylinder, a supply reservoir, an outlet passage, an oscillatory rotary valve for controlling flow through said transfer port and oscillatable between an intake position wherein it establishes communication from said supply reservoir to said transfer port and a discharge position wherein it establishes communication from said transfer port to said outlet passage, driving means for continuously reciprocating said piston, mechanism for oscillating said valve between said two positions in timed relationship to the reciprocation of said piston whereby fluid from said reservoir is delivered to said outlet passage, and means included in said driving means for varying the quantity of fluid delivered by said pump, said means including a rotary eccentric comprised of a pair of offset cams and a follower fork said follower fork having its arms offset so that one arm follows one of said offset cams and the other arm follows the other of said offset cams, an oscillatable crank arm connected to said piston for reciprocating said piston, a lever connecting said follower fork to said crank arm, said lever having a stationary pivot intermediate its ends, and means for shifting said pivot along the length of said lever whereby the stroke of said pump may be varied.

'7. A pump comprising a pump cylinder having a transfer port connected therewith, a piston reciprocable in said cylinder, a supply reservoir, an outlet passage, an oscillating rotary valve for controlling flow through said transfer port and oscillatable between an intake position wherein it establishes communication from said supply reservoir to said transfer port and a discharge position wherein it establishes communication from said transfer port to said outlet passage, driving means for continuously reciprocating said piston, said driving means including a connecting rod, a crank arm and a slipper block said slipper block being coupled to said piston such that when said crank arm is oscillated said connecting rods communicate reciprocated vertical motion to said piston, mechanism for oscillating said valve between said two positions in timed relationship to the reciprocation of said piston whereby fluid from said reservoir is delivered to said outlet passage, spring-pressed wedge pins adjacent to said rotary valve in opposed relationship with said ports to press said valve tightly against said ports to prevent leakage of fluid about said valve, and means coupled to said mechanism for relaxing pressure on said wedge pins during intervals when said valve is in oscillatory motion.

8. A pump comprising a pump cylinder having a transfer port connected therewith, a piston reciprocable in said cylinder, a supply reservoir, an outlet passage, an oscillating rotary valve for controlling flow through said transfer port oscillatable between an intake position and a discharge position wherein it establishes communication from said supply reservoir to said transfer port and it establishes communication from said transfer port to said outlet passage, driving means for continuously reciprocating said piston, mechanism for oscillating said valve between said two positions in timed relationship to the reciprocation of said piston whereby fluid from said reservoir is delivered to said outlet passage, spring-pressed wedge pins adjacent to said rotary valve in opposed relationship with said ports to press said valve tightly against said ports to prevent leakage of fluid about said valve, and means coupled to said mechanism for relaxing pressure on said wedge pins during intervals when said valve is in oscillatory motion, said pressure relaxing means comprising a wedge positioned such that one side of said wedge makes contact with said valve, a spring against one end surface of said wedge, and a cam positioned to ride along the other end surface of said wedge such that said spring presses said wedge against said cam and causes said wedge to press against said valve, said cam being shaped to provide an interval during which said spring may expand, said expansion of said spring relaxing the pressure of said wedge against said valve and permitting oscillatory motion of said valve.

(References on following page) UNITED References Cited by the Examiner STATES PATENTS Behr 251-161 Darling 251188 VVenkenWender 103 3 8 Hodges 1033 8 Bagby 10338 Cozzoli 1033 8 Moule 1033 8 Morine 103-38 Erikson 103-3 8 Martin 103-38 Longenecker 103-227 Moller 103227 Rehlander 103-3 8 Machen 1033 8 Vargo 103-3 8 FOREIGN PATENTS Great Britain.

LAURENCE V. EFNER, Primary Examiner. 

1. A PUMP COMPRISING A PUMP CYLINDER HAVING A TRANSFER PORT CONNECTED THEREWITH, A PISTON RECIPROCABLE IN SAID CYLINDER, A SUPPLY RESERVOIR, AN OUTLET PASSAGE, AN OSCILLATING ROTARY VALVE FOR CONTROLLING FLOW THROUGH SAID TRANSFER PORT AND OSCILLATABLE BETWEEN AN INTAKE POSITION WHEREIN IT ESTABLISHES COMMUNICATION FROM SAID SUPPLY RESERVOIR TO SAID TRANSFER PORT AND A DISCHARGE POSITION WHEREIN IT ESTABLISHES COMMUNICATION FROM SAID TRANSFER PORT TO SAID OUTLET PASSAGE, DRIVING MEANS FOR CONTINUOUSLY RECIPROCATING SAID PISTON, MECHANISM FOR OSCILLATING SAID VALVE BETWEEN SAID TWO POSITIONS IN TIME RELATIONSHIP TO THE RECIPROCATION OF SAID PISTON WHEREBY FLUID FROM SAID RESERVOIR IS DELIVERED TO SAID OUTLET PASSAGE SPRING-PRESSED WEDGE PINS ADJACENT TO SAID ROTARY VALVE IN OPPOSED RELATIONSHIP WITH SAID PORTS TO PRESS SAID VALVE TIGHTLY AGAINST SAID PORTS TO PREVENT LEAKAGE OF FLUID ABOUT SAID VALVE, AND MEANS COUPLED TO SAID MECHANISM FOR RELAXING PRESSURE OF SAID WEDGE LOCKS DURING INTERVALS WHEN SAID VALVE IS IN OSCILLATORY MOTION. 